Lake-Effect Snow

weather · lakes · snow

Cold air meets warm water. Lake-effect snow happens when a cold air mass moves across a warm lake. The contrast between the icy air and the warmer water is what makes this special kind of snow happen.

Air rises and cools. The warm lake water heats the air touching it, causing the air to rise. As it rises higher into the colder atmosphere, the water vapor in the air freezes into ice crystals.

Water vapor gets picked up. The rising warm air pulls tons of water vapor directly from the lake surface. This gives the snow clouds an amazing amount of moisture to work with.

Snow falls downwind. The frozen water vapor falls as snow on the leeward shore, which is the side of the lake facing the direction the wind is blowing. This is why some towns near the Great Lakes get buried in snow while others nearby stay dry.

Incredible snowfall amounts. Lake-effect snow can dump several feet of snow in just a single day, making it one of nature's most intense snowstorms. It happens most in fall and early winter when the lake is still warm but the air is freezing cold.